This site uses cookies. By continuing to browse the ConceptDraw site you are agreeing to our Use of Site Cookies.
"An ER model is an abstract way of describing a database. In the case of a relational database, which stores data in tables, some of the data in these tables point to data in other tables - for instance, your entry in the database could point to several entries for each of the phone numbers that are yours. The ER model would say that you are an entity, and each phone number is an entity, and the relationship between you and the phone numbers is 'has a phone number'. Diagrams created to design these entities and relationships are called entity–relationship diagrams or ER diagrams.
Using the three schema approach to software engineering, there are three levels of ER models that may be developed. ...
Conceptual data model ... is the highest level ER model in that it contains the least granular detail but establishes the overall scope of what is to be included within the model set.
Logical ER model ... contains more detail than the conceptual ER model. In addition to master data entities, operational and transactional data entities are now defined.
The physical ER model is normally developed to be instantiated as a database. Therefore, each physical ER model must contain enough detail to produce a database and each physical ER model is technology dependent since each database management system is somewhat different.
Physical model ... is normally forward engineered to instantiate the structural metadata into a database management system as relational database objects such as database tables, database indexes such as unique key indexes, and database constraints such as a foreign key constraint or a commonality constraint." [Entity–relationship model. Wikipedia]
This crow's foot entity-relationship diagram (ERD) example "Educational data base" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park.
ERD
ERD, entity,

entity-relationship diagram, ER-diagram, database ERD Entity-Relationship Diagram (ERD)

entity-relationship diagram, ER-diagram, database ERD
Entity-Relationship Diagram (ERD) solution extends ConceptDraw PRO software with templates, samples and libraries of vector stencils from drawing the ER-diagrams by Chen's and crow’s foot notations.
HelpDesk

How To Make a Crow's Foot ER Diagram

The Crow's Foot ERD notation is often used in software engineering and database design. The originator of Crow’s Foot notation was Gordon Everest, who offered the idea of how to visually represent the different types of relationships that can exist between objects in an entity relationship diagram (ERD). The Crow’s Foot notation is often used in ER models to how a particular table data can reference data in other tables within a database. The free Crow's Foot Notation solution for ConceptDraw PRO offers a complete vector stencil library containing full standardized symbols of Crow's Foot notation.

entity-relationship diagram, ER-diagram, database ERD Entity-Relationship Diagram (ERD)

entity-relationship diagram, ER-diagram, database ERD
An Entity-Relationship Diagram (ERD) is a visual presentation of entities and relationships. That type of diagrams is often used in the semi-structured or unstructured data in databases and information systems. At first glance ERD is similar to a flowch

Professional Diagram and Flowchart Software

ConceptDraw PRO is a Mac OS X and Windows platforms professional software to draw your own business process diagrams and flowcharts.

MS Visio Look a Like Diagrams

No need for any special drawing skills to create professional looking diagrams outside of your knowledge base. ConceptDraw PRO takes care of the technical details, allowing you to focus on your job, not the drawing.
ConceptDraw PRO delivers full-functioned alternative to MS Visio. ConceptDraw PRO supports import of Visio files. ConceptDraw PRO supports flowcharting, swimlane, orgchart, project chart, mind map, decision tree, cause and effect, charts and graphs, and many other diagram types.

ConceptDraw Solution Park ConceptDraw Solution Park

ConceptDraw Solution Park
ConceptDraw Solution Park collects graphic extensions, examples and learning materials

How to Help Customers be More Productive

Presenting you with a drawing program which could really surprise you with their great functionality.

Don't know how to start to draw Connector's improvement?
Curious how should diagramming software work?

Drawing programs involve a lot of things like designs in an illustrative way, creating an cherts, Tools to create high end graphics, create dashboards, using your data and many other technical aspects do it in a much professional and in a quick way.